# ELDI2002 - Control for Digital Electric Energy

### Examination arrangement

Examination arrangement: Aggregate score

Evaluation Weighting Duration Grade deviation Examination aids
Oral exam 30/100 30 minutes E
Portfolio 70/100 A

### Course content

Linear and nonlinear state-space modelling applied to relevant modern electrical engineering examples—including but not limited to power converters, electrical machines, wind turbines, etc. Equilibrium analysis. Introduction to industry-standard linear control structures: open loop equilibrium control, P, PI, PID control, full-state feedback and manual tuning. Time-responses in Simulink, phase portraits analysis in Matlab. Linearization of nonlinear models. Modal transformation and eigenvalue analysis (including parametric sweeps and sensitivity analysis). Frequency domain analysis via Laplace transformation, transfer functions, block diagrams, and performance specifications of second-order systems. Frequency response, bode-plots, relative stability (gain margin and phase margin), design of cascaded compensators (lead/lag) using Bode plots. Controllability and observability and integrated design of full-state feedback control with observers.

### Learning outcome

Knowledge:

After completing the course, the student will have acquired knowledge about mathematical modelling of at least one of the most relevant dynamical power devices (converters, machines, turbines, etc.) in the time- and frequency-domain. The student will have gained understanding on the main differences between linear and nonlinear (electrical) systems, and how to characterize their equilibrium, and control them by means of (manually-tuned) state-feedback and P, PI, PID controllers. The student will become familiar with the most relevant modelling formalisms used in modern electrical engineering practice such as state-space modelling, transfer functions and block diagrams. In addition, the student will learn how to linearize nonlinear systems, and assess its small-signal stability by means of an eigenvalue analysis. Moreover, the student will be able to derive useful (open-loop) transfer functions from their linearized system, analyze their stability by means of their pole locations, represent them by means of block diagrams and obtain closed-loop transfer when cascaded with a compensator. Furthermore, the student will learn basic techniques to approximate resulting closed-loop transfer functions to simpler second-order ones (without zeros), such as to enforced a desired dynamical performance in terms of e.g.: percent overshoot, peak/rise-time, etc. They will also get familiar with the final value theorem as a useful tool to guarantee desired steady-state errors for different inputs (step, ramp, etc.). In addition, the student will learn about how to perform a frequency response with their system and sketch approximated Bode plots. They will gain understanding of relative stability concepts such as phase and gain margins, will be able to identify these directly in the Bode plot, as well as improve them by adding a lead or lag compensator. Finally, the students will gain understanding on the all-important controllability and observability concepts, widely used in control engineering and learn how to check if their systems are controllable and observable. They will also learn to design integrated full-state feedback and observer.

Skills:

Know how to model and analyze stability of dynamical electrical systems relevant in modern electric power engineering, set their control objectives and design and synthetize stabilizing and performant controllers.

General competence:

Be able to carry out small development projects independently and contribute actively in the classroom. Increased report writing skills as well as communication skills. Increased Simulation (Simulink) skills as well as numerical computation skills (Matlab).

### Learning methods and activities

Live (physical) theorethical lectures once every two weeks supported by offline in-depth and mathematically rigorous video tutorials combined with an presential workshops two or three sessions a week where students work on weekly assignments under the supervision of the lecturer and scientific/student assistants—which allows for one-on-one interaction between students and the teaching staff. Assignments will be a mixture between theoretical developments, computations in Matlab as well as time-domain simulations in Simulink on relevant applications for modern electric power engineering.

### Further on evaluation

30% Oral exam, 70% Assignments+Project.

Assignments and project:

Five small written assignments of 1-2 pages each.

Assignment 1: Equilibrium analysis and direct equilibrium open-loop control.

Assignment 2: PID and state feedback control with manual tunning.

Assignment 3: Linearization of nonlinear model, validation, and small-signal stability .

Assignment 4: Transfer function modelling, and performance specifications in the s-domain.

Assignment 5: Frequency response, Bode and lead-lag controller design.

Assignment 6: Observability and Controllability + Integrated full state feedback and observer design.

Each assignment will be graded along the way using a "Fail, Pass, Good, Brilliant" scale. At the end of the course, students will get an opportunity to resubmit previous assignments for re-evaluation.

In addition, there will be a 30% oral exam at the end of the course.

### Required previous knowledge

Calculus 1 (TMA4100) and 2 (TMA4105).

### Course materials

Offline video tutorials.

Book: Richard Dorf, Robert Bishop: Modern Control Systems.

More on the course

No

Facts

Version: 1
Credits:  7.5 SP
Study level: Intermediate course, level II

Coursework

Term no.: 1
Teaching semester:  AUTUMN 2023

Language of instruction: English

Location: Trondheim

Subject area(s)
• Engineering Cybernetics
• Electrical Power Engineering
Contact information
Course coordinator:

Department of electric energy

# Examination

#### Examination arrangement: Aggregate score

Term Status code Evaluation Weighting Examination aids Date Time Examination system
Autumn ORD Portfolio 70/100

Release
2023-12-04

Submission
2023-12-04

11:00

12:00

Autumn ORD Oral exam 30/100

Release
2023-12-04

Submission
2023-12-04

10:00

11:00

Summer UTS Oral exam 30/100
• * The location (room) for a written examination is published 3 days before examination date. If more than one room is listed, you will find your room at Studentweb.
Examination

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